The present invention relates to a descent controller for use on a rope or line or cable for lowering a person or load in a controlled descent from a higher elevation to a lower elevation. More particularly, the present invention relates to a rope or cable mounted descent control device having a compact design and wherein the operating components are substantially enclosed.
Numerous descent assistance devices have been developed, all with the objective of aiding in the lowering of a load from a higher to a lower elevation. These devices have taken many forms and have utilized a variety of elements capable of providing a mechanical advantage together with a braking mechanism. In more recent years, concerns with occupational safety have led to the development of mechanisms that enable a worker to lower himself from an elevated position such as a scaffold, crane, lift truck or platform in the event of an emergency.
A descent control device with a deadman brake, in the form of a vertical cylindrical drum or capstan about which a rope is wound and a tapered slot through the drum for receiving and releasably gripping the rope along which descent is made, together with a releasable locking end plate, is shown in U.S. Pat. No. 5,131,491, issued Jul. 21, 1992, to H. M. Varner and R. H. Frost. While the above device is well designed and effective, it is desirable in some applications to reduce overall size and number of operating components. It is also desirable to enclose the operational components in some applications to lessen the potential for contamination or damage.